GM9S96 Service Manual
SERVICING
40
WARNING
1. -
-
partment door to gain access to the gas valve.
2. Connect a calibrated manometer (or appropriate gas
pressure gauge) at the gas valve outlet pressure
tap. Refer to Measuring Gas Pressure: Single Stage
Valves
connections.
WARNING
3. Turn ON the gas and electrical power supply and op-
erate the furnace.
4.
Adjust manifold pressure using the table below.
3.5" w.c.
10.0" w.c.
-
5. White-Rodgers 36J22 Valves:
a. Back outlet pressure test screw (inlet/outlet pres-
sure boss) out one turn (counterclockwise, not
more than one turn).
b. Attach a hose and manometer to the outlet pres-
sure outlet pressure boss.
c. Turn ON the gas supply.
d. Turn on power and close thermostat “R” and “W1”
contacts to provide a call for heat.
e. Measure the gas manifold pressure with burners
Manifold
Gas Pressure table shown below.
f. Remove regulator cover screw from the outlet
pressure regulator adjust tower and turn screw
clockwise to increase pressure or counterclock-
wise to decrease pressure. Replace regulator
cover screw.
g.
system.
h. Remove the manometer hose from the hose barb
i. Turn outlet pressure test screw in to seal pressure
port (clockwise, 7 in-lb minimum).
6. Honeywell VR8215 Valve:
a. Remove the outlet pressure boss plug. Install an
tap.
b. Attach a hose and manometer to the outlet pres-
c. Turn ON the gas supply.
d. Turn on power and close thermostat “R” and “W1”
contacts to provide a call for low stage heat.
e. Measure the gas manifold pressure with burners
Manifold
Gas Pressure table shown.
f. Remove regulator cover screw from the outlet
pressure regulator adjust tower and turn screw
clockwise to increase pressure or counterclock-
wise to decrease pressure. Replace regulator
cover screw.
g.
system.
h. Remove the manometer hose from the hose barb
i. -
let pressure tap. Replace the outlet pressure boss
plug and seal with a high quality thread sealer.
WARNING
-
7. Turn on gas to furnace and check for leaks. If leaks
are found, repair and then reinstall burner compart-
ment door.
8. Turn on electrical power and verify proper unit operation.
Pressure Regulator
Adjustment
(Under Cap Screw)
Gas Valve
On/Off
Selector
Switch
INLET
OUTLET
Inlet Pressure
Tap
Outlet Pressure
Tap